I don't get the sense that JA wanted us to share Mr Elliott's view of Anne's motives in visiting Mrs Smith, - his delight and his praise are altogether too gushing and overblown to be trusted, IMO. I also think he is misreading Anne's motives.

I agree with you that her visiting Mrs Smith would be prompted by 'common decency', both in recognition of past kindness and because of Mrs Smith's current difficulties. At the same time I think Anne also visited simply because she wanted to.

Poor Anne has had few enough people in her life who had been positively kind to her, and because of Mrs Smith's kindness she "could never be remembered with indifference". So I believe her visits are motivated not only by mere common decency but by genuine warmness of heart towards someone she has very positive memories of.

Also, Anne "almost ventured to depend" on Mrs Smith's "good sense and agreeable manners". There has been a sad lack of such people Anne's life, so I believe she would have been eager to renew the acquaintance whatever Mrs Smith's circumstances, simply in the hope of having another such person to talk to as well as because of her past kindness.

So, no medals for Anne's nobility and benevolence, but I do like her warm-heartedness and am glad she has renewed a rewarding friendship.